Glucose-based total parenteral nutrition does not stimulate glucose uptake by humans tumours

BACKGROUND: Since glucose represents the preferred fuel for cancer cells, there is some debate about the potential stimulation of tumour metabolism induced by a glucose-based total parenteral nutrition (TPN) in cancer patients. METHODS: We investigated the uptake of 18]2-fluoro-2-deoxy-D-glucose (FDG) through the positron emission tomography of the healthy liver and of the tumour in 12 patients with liver metastases from colorectal cancer. We determined whether FDG uptake by the tumour in fasting conditions was affected by the subsequent administration of a glucose-based (GTPN) or a lipid-based (LTPN) containing glucose 4 mg/kg/min or lipid 2 mg/kg/min, respectively, as non-protein energy source. RESULTS: The data showed that FDG uptake by the metastases was 3-3.6 times higher than by the healthy liver in fasting conditions and it was not significantly affected by the subsequent administration of GTPN or LTPN. CONCLUSIONS: We speculated that, despite glucose being the preferred fuel for cancer cells, its disproportionately high uptake even in fasting conditions makes the glucose consumption unable to be modulated by a further supply of glucose or lipid.